No cheating is not cheating. That is too simplistic and absolute.
A deep and meaningful relationship vs dating or something more superficial. The amount of trust is proportionate.
If I am dating some one, all they should expect is the time I spend with them. Even if I am going out with them, but the level of commitment is not deep, there is no obligation on my part to not keep looking for something better.
Once I have made that promise to be with that person and only that person, then if I decide to see other people, can it be considered cheating.
Just because we see each other, have sex, and what not does not mean you own me. Nor does it mean I own you. When you outright promise yourself to another, then breaking that promise in the way we are talking about can it be called cheating.
If you decide to trust some one, more than what is called for, you may think you are being cheated on, but there is the other half who may consider it different.
Lastly, just because you promised yourself to some one does not mean you have control over them. If you do not keep up your efforts in the relationship, then if your partner decides to seek some one else, that is half your blame.
That is why I laugh at the idea of any woman cutting their boyfriend off from sex because of some issue they have. What do you honestly think is going to happen when you use sex/ love making as leverage in a relationship? That goes the same with married people as well, but to differing degrees.